a second time". The bug was caused by incompatibility of
negations elimination algorithm and PS: during first statement
execute a subtree with negation was replaced with equivalent
subtree without NOTs.
The problem was that although this transformation was permanent,
items of the new subtree were created in execute-local memory.
The patch adds means to check if it is the first execute of a
prepared statement, and if this is the case, to allocate items
in memory of the prepared statement.
The implementation:
- backports Item_arena from 5.0
- adds Item_arena::is_stmt_prepare(),
Item_arena::is_first_stmt_execute().
- deletes THD::allocate_temporary_pool_for_ps_preparing(),
THD::free_temporary_pool_for_ps_preparing(); they
were redundant.
and adds a few invariants:
- thd->free_list never contains junk (= freed items)
- thd->current_arena is never null. If there is no
prepared statement, it points at the thd.
The rest of the patch contains mainly mechanical changes and
cleanups.
When in find_item_in_list() we are looking for item we should take into account unaliased
names of the fields but only if item with such aliased name is not found.
Also we should ignore aliases when looking for fully specified field.
Instead of trying to open time zone tables during calculation of CONVERT_TZ() function
or setting of @@time_zone variable we should open and lock them with the rest of
statement's table (so we should add them to global table list) and after that use such
pre-opened tables for loading info about time zones.
Note: The following tests fails
- fulltext (Sergei has promised to fix)
- rpl_charset (Guilhem should fix)
- rpl_timezone (Dimitray has promised to fix)
Sanja needs to check out the calling of close_thread_tables() in sp_head.cc
Post-merge fixes for nested joins.
The join_tab_cmp function in sql_select has been changed.
join_nested.result:
Post-merge fixes for nested joins.
The join_tab_cmp function in sql_select has been changed
sql_select.cc:
Post-merge fixes for nested joins.
Avoided re-execution of eliminate_not_funcs and simplify_joins
in optimize_cond.
Changed the join_tab_cmp function to take into account
the dependent relation.
sql_lex.cc, sql_lex.h:
Added the first_cond_optimization flag to st_select_lex to avoid
re-execution of some optimizations in optimize_cond.
sql_base.cc:
Post-merge fixes for nested joins.
Fixed problems with a proper column list substituted for '*' in
queries with natural joins.
Added basic per-thread time zone functionality (based on public
domain elsie-code). Now user can select current time zone
(from the list of time zones described in system tables).
All NOW-like functions honor this time zone, values of TIMESTAMP
type are interpreted as values in this time zone, so now
our TIMESTAMP type behaves similar to Oracle's TIMESTAMP WITH
LOCAL TIME ZONE (or proper PostgresSQL type).
WL#1266 "CONVERT_TZ() - basic time with time zone conversion
function".
Fixed problems described in Bug #2336 (Different number of warnings
when inserting bad datetime as string or as number). This required
reworking of datetime realted warning hadling (they now generated
at Field object level not in conversion functions).
Optimization: Now Field class descendants use table->in_use member
instead of current_thd macro.
Final version of patch.
Adds support for specifying of DEFAULT NOW() and/or ON UPDATE NOW()
clauses for TIMESTAMP field definition.
Current implementation allows only one such field per table and
uses several unireg types for storing info about this properties of
field. It should be replaced with better implementation when new
.frm format is introduced.
table resolution".
Added members to Item_ident for storing original db, table and field
names since those that set later from Field have shorter life-time
than required by prep. stmt. So we need to restore original names in
Item_ident::cleanup(). Also now using special construnctor for creation
of Item_field from Field object that ensures that table and field name
have big enough life-time.
"Fix" for bug #2050 "10 to 1 performance drop with server 4.1.1"
Clean ups in implementation of caching of field number in table.
Added caching of table in which field is found in find_field_in_tables().
This is to enable table handlers to implement online create/drop index.
It consists of some parts:
- New default handler methods in handler.h
- Split of mysql_alter_table. It decides if only one kind of
alteration is to be done (e.g. only create indexes or only drop
indexes etc.) It then calls the specialized new handler method if
the handler implements it. Otherwise it calls real_alter_table.
- The parser sets flags for each alter operation detected in a
command. These are used by mysql_alter_table for the decision.
- mysql_prepare_table is pulled out of mysql_create_table. This is
also used by mysql_create_index to prepare the key structure array
for the handler. It is also used by mysql_create_index and
mysql_drop_index to prepare a call to mysql_create_frm.
- mysql_create_frm is pulled out of rea_create_table for use by
mysql_create_index and mysql_drop_index after the index is
created/dropped.
Thanks to Antony who supplied most of the changes.
